The truth about grass – five myths busted

For many years, sports turf managers, field architects and community leaders didn’t have much choice about the field surface they used. There were different varieties of grass available, but the primary focus was maintaining the field to maximize playability and player safety.

The introduction of artificial turf in 1964, the recent development of different artificial turf surfaces and infills, and scientific engineering of new grass varieties that incorporate preferred characteristics provide stadium owners, schools and communities with many more options for building and maintaining their athletic fields.

Deciding which surface to install is often made more difficult because there is a great deal of outdated or incorrect information about natural grass that is accepted as truth. Here, we shine a light on and debunk some common misconceptions about grass:

Myth #1: Natural grass is more expensive than artificial turf

Studies comparing the costs of installing and maintaining natural grass and artificial turf fields show that overall costs for the two playing surfaces are comparable. In determining lifecycle costs, researchers calculated the following expenses (calculations include costs for labor and materials):

• Field preparation and turf installation;

• Maintenance;

• Removal and disposal.

No single dollar estimate exists for installing and maintaining natural or synthetic fields. This is due to the variability of quality and the cost to prepare fields, different materials for installation and maintenance, and regional disparities in labor costs. For example, there are different soil preparations and different varieties of natural grass that can be used and, similarly, different types of plastic and infill that can be used for artificial turf fields. Local climates, the frequency with which the field is used, the types of activities staged on the fields, and budgets all must be considered when deciding which materials to use. All of these components contribute to the longevity and playability of the surface.

A study developed by John Sorochan, an associate professor of Turfgrass Science and Management at the University of Tennessee, USA, determined that over the course of a single year, installation and maintenance costs of an average artificial turf field were US$138,025, while the costs for an average natural grass field were US$152,739.

However, when Sorochan’s research team factored in the costs of maintaining the different fields and replacing the surfaces over a 10-year period, the average annual cost comparisons changed dramatically: US$218,025 per year over a period of 10 years for artificial turf versus US$103,739 per year over the same period for natural grass. (1)

Similar studies produce comparable results: In May 2005, Amy Fouty, a certified sports field manager (CSFM) at Michigan State University, made a presentation during the Synthetic Turf Infill Seminar during which she cited the annual maintenance costs (maintenance only, not installation) of artificial turf fields from US$13,720 to US$39,220. The annual maintenance costs for natural grass fields were US$8,133-$48,960. (2)

Whenever possible, a trained sports turf manager should maintain an athletic field, regardless of the surface used. A CSFM has undergone rigorous training to ensure professionalism, commitment to excellence, accountability, dedication to cost effective facility management and commitment to field safety.

Natural grass requires regular maintenance before, during and after the playing season to keep it healthy and ensure that the surface remains safe for athletes and recreational users. Mowing, fertilization, and irrigation are the primary cultural practices applied to keep fields healthy.

In addition, careful field managers are mindful about keeping the playing surface level, ensuring grass coverage, and including cultural practices that control and reduce compaction. Annual maintenance programs should include seeding, sodding or sprigging for adequate grass coverage, adding topdressing to help level the field and fill in low areas, and aerifying to reduce soil compaction. With the correct application of cultural practices, natural grass fields can provide a desirable playing surface with a reduced risk for injury.

The myth is that artificial turf fields don’t require any maintenance. Those who aren’t trained athletic field managers commonly believe once you install artificial turf, you never have to do anything further! Professional turf managers understand that to be a fallacy. Artificial turf fields require regular maintenance to keep the surface playable. Maintenance includes redistributing and replenishing the infill to keep the surface from getting too hard, weekly brushing of the plastic blades, regular spraying to reduce static, and twice-yearly grooming.

Both natural grass and artificial turf can grow weeds and house insects. Weeds are introduced on artificial turf in similar ways to natural grass – foot and vehicular traffic, wind, and animals transport dirt and seeds to fields. Thus, watching for pests becomes an important part of field maintenance regardless of the surface, and treating for pests may be necessary.

Myth #3: Natural grass uses too many resources

Many homeowners use much more water, fertilizer and chemicals to maintain natural grass than is needed – or even recommended – for the health of the grass, leading to the myth that natural grass uses far more resources than other groundcovers.

In truth, irrigating less frequently and more thoroughly strengthens the grass plant by encouraging the roots to grow deep into the soil, making the grass stronger and less susceptible to being pulled up by activity. Here, again, a trained sports turf manager will assess the grass variety, the soil composition on the field and the local climate to compose a schedule for irrigation, mowing, fertilizing and seeding.

Scientists are constantly introducing new varieties of natural grass that are bred to take advantage of desirable attributes. Natural grass is now available that is drought-tolerant (uses less water), slow growing (needs to be mowed less often) and more resistant to pests (requiring less use of chemicals).

• Reducing the volume of stormwater run-off through evapotranspiration.

Natural grass does require water and fertilizer to maintain a healthy and safe playing surface. In some instances, pest control may be necessary for natural grass fields as well. However, natural grass provides numerous environmental benefits to offset the necessary inputs.

By demonstrating restraint and using the right amount of water, fertilizer and chemical treatments, natural grass fields offer communities far more environmental, health and social benefits then detriments.

Myth #4: Natural grass isn’t an option for indoor stadia

Several innovations have made it possible to offer natural grass for indoor use. Look no further than the University of Phoenix football stadium, home of the Arizona Cardinals, which is consistently rated the best natural grass field in the National Football League.(3) The entire grass pitch can be rolled outside so the field can get the fresh air and sunlight it needs to thrive.

Of course, a mobile sports field isn’t a practical option for many high school and community fields. But for indoor stadia with retractable roofs, most of the needed air and sunlight comes from opening the roof during daylight hours. And for areas of the field that don’t get adequate sunlight, or for stadia that don’t offer retractable roofs, special grow lamps have been engineered to nourish natural grass. Amsterdam Arena in the Netherlands has been using these lamps successfully since 2008, with dozens of other indoor and outdoor facilities around the world implementing their use.

The city of New York is introducing a new way to grow grass using a system that will capture and reflect sunlight and redirect it below ground. New York planners are using this technology to develop an underground park in a defunct subway station, called The Lowline, that will feature living grass, plants and trees. If successful, this could offer another option for providing natural grass at indoor stadia.

Myth #5: Natural grass gets worn out quickly

With regular care and by taking advantage of new wear-tolerant grass varieties, natural grass fields can look great, play great and stand up to robust activity. Jerad Minnick, lead advisor for the Natural Grass Advisory Group, has described how, by combining techniques that help grass recover, grass fields can host as many activities as artificial turf fields.

Aggressive aeration – because active play on natural grass causes soil compaction, it is important that the soil is aerated regularly during frequent use so that air is available to grass roots. Some fields may find success with weekly aeration, especially in high-traffic areas. Aeration improves plant access to air, water and nutrients, and reduces soil compaction.

Traffic management – reconfiguring a field so that traffic patterns are shifted is another way of ensuring long-term grass health. Rotating the playing field by 90°, using the field for diverse activities or merely shifting the field lines by a few yards will help to prevent repeated wear patterns and soil compaction. Concentrating topdressing, aeration and fertilization to worn areas assists with recovery and reduces the overall demand of trying to maintain an entire field.

Turfgrass varieties – new, more wear-tolerant grass varieties are being developed to withstand increased use. Grass breeders are continually working on developing grasses that can withstand damage and repair more quickly for use on highly trafficked fields.

Minnick advises that with regular maintenance during the sports season, natural grass fields can withstand increased use. Do not wait until the end of the season to implement cultural practices. He has seen success on a professional field used for 10 football games, five soccer games, and a concert over a five-week period which is showing no obvious wear and remains in regular use.

Natural grass is a hearty, healthy, player-friendly choice for athletic fields serving schools, park districts and professional sports. If you are among those deciding what surface should be used to build an athletic field, make sure you thoroughly research all of your options and consider the short- and long-term costs and benefits of natural grass.

Endnotes

(1) Sorochan, John. “Understanding and Managing Synthetic Turf” presentation for the University of Tennessee, Center for Athletic Field Safety.